Epitaxial ZnO thin films have been grown on 2-in diameter Si(111) substrates by atmospheric-pressure metalorganic chemical vapor deposition. An initial At layer with a thickness of 10 angstrom was deposited in order to protect the Si surface from oxidation. The structural property was characterized using a double-crystal X-ray diffractorneter, and the photoluminescence spectra were measured using the excitation of 325 nm line of a He-Cd laser. The minimum full-width at half-maximum (FWHM) of the diffraction peak of ZnO(002) is 0.35 degrees and 0.16 degrees for the omega and omega - 2 theta scans, respectively. Free-exciton emission with a shoulder at the bound-exciton peak was observed at 10K. Microscopic images show cracks for the sample of 3.0 mu m thickness, and the crack density is about 7.6 x 10(2)/cm(-1). The maximum area of a crack-free triangular region is bout 1756 mu m(2). (c) 2004 Elsevier B.V. All rights reserved.